In the depths of ancient history there were four kingdoms, Fire-Water-Earth and light the most powerful powers among the others that only the royal family should have fire for fire, water for water, earth for earth and light for light

The four Kingdoms had their own reputation in the world

North - Fire: love of domination and control

West - Water: Tolerance and reconciliation

East - Earth: destroy

South - Light: isolation but union

And for more than 15 years the 4 kingdoms had a barrier divide each one from the other forbidding anyone to come in or out just in the rare cases with the acceptance of the kings

Chanyeol is the only son of the fire king who made a mistake one day in entering the light kingdom border

Baekhyun is the second son with his big sister from his father (future queen of the light kingdom) who will do anything for his nation

Kai is the 2nd son of the water Kingdome with one older brother (Suho) born with a no-water power

D.O is the 1st son and soon-to-be king of earth kingdom